Transient solid hold-up signals were registered in a cold fluidized bed and statistically analyzed. Particle agglomerates in the emulsion phase were identified from signals and the agglomerate properties were investigated. The volume fraction of the transient solid holdup signals varied from 0.05 to 0.72. Mean solid holdup of particle agglomerates in the emulsion fluctuated in the range of 0.552~0.562, barely influenced by switch of operation pattern. The volume fraction of the particle agglomerates decreased first and then increased with increasing superficial gas velocity, varying over a range of 0.01~0.5 with flow regimes. Agglomerate frequency varied over the range of 0.02~1.6 Hz and the duration time was less than 0.12 s in most cases.